A prospective study of sexual transmission of human T lymphotropic virus (HTLV)-I and HTLV-II

J Infect Dis. 2005 May 1;191(9):1490-7. doi: 10.1086/429410. Epub 2005 Mar 31.

Abstract

Background: Cross-sectional studies support sexual transmission of human T lymphotropic virus (HTLV)-I/II; however, prospective incidence data, particularly for HTLV-II, are limited.

Methods: A cohort of 85 HTLV-positive (30 with HTLV-I and 55 with HTLV-II) blood donors and their stable (>or=6 months) heterosexual sex partners were followed biannually over the course of a 10-year period.

Results: Four of 85 initially seronegative sex partners of HTLV-I and -II carriers seroconverted, for an incidence rate (IR) of 0.6 transmissions/100 person-years (py) (95% confidence interval [CI], 0.2-1.6). This includes 2 HTLV-I transmissions/219 py (IR, 0.9 transmissions/100 py [95% CI, 0.1-3.3]) and 2 HTLV-II transmissions/411 py (IR, 0.5 transmissions/100 py [95% CI, 0.06-1.8]), with no significant difference by HTLV type. There were 2 male-to-female (IR, 1.2 transmissions/100 py [95% CI, 0.1-4.3]) and 2 female-to-male (IR, 0.4 transmissions/100 py [95% CI, 0.05-1.6) transmissions. HTLV-I or -II proviral load was 2 log10 lower in newly infected partners than in index positive partners who transmitted HTLV (P=.007).

Conclusions: The incidence of sexual transmission of HTLV-II may be similar to that of HTLV-I, and female-to-male transmission may play a more important role than previously thought. HTLV-I and -II proviral load may be lower in sexually acquired infection, because of a small infectious dose.

Publication types

  • Clinical Conference
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Cohort Studies
  • Cross-Sectional Studies
  • Female
  • HTLV-I Infections / epidemiology
  • HTLV-I Infections / transmission*
  • HTLV-II Infections / epidemiology
  • HTLV-II Infections / transmission*
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Risk Factors
  • Sexually Transmitted Diseases / epidemiology
  • Sexually Transmitted Diseases / transmission*
  • Sexually Transmitted Diseases / virology*
  • Socioeconomic Factors
  • United States / epidemiology